This invention relates to radiant metal panels fabricated by assembly of extruded modules, and in particular to ways and means for securing the assembly together while accommodating thermally-induced dimensional changes such as caused by temperature variation.
It is common to make panels by securing together several adjacent elongated modules. Tubes or pipes are secured to the back of the modules to conduct heat exchange medium therepast. Panels of this type are used in highly visible areas, such as meeting rooms, offices, and the like, where it is necessary that the face of the panel be and remain flat and neat appearing under all conditions. At the same time, for many reasons, the panel members should be of high heat conductivity and as light weight as possible.
In a usual construction, individual modules are of tongue and groove design, with a tongue along one side edge and a complemental groove along the other edge. Adjacent modules are fitted together, the grooves of one being crimped onto the tongue of another to hole them in assembled position. A plurality of spaced-apart rigid stiffeners are then secured transversely across the back of the panel and fixed individually to all the several modules to hold them securely as a flat rigid panel. The stiffener is also a straightener which contacts the modules in a straight line. Such construction, although widely used, does have some drawbacks. This is so because when all modules are fixed to the stiffener as in the prior construction, there is no relative movement possible between modules and stiffener, hence the panel cannot accommodate thermally-induced dimensional variations. When heat causes the modules to expand, the individual panel modules, being fixed to the stiffener, will buckle or fracture connections to the stiffener and/or cause the stiffener to bend. The stiffeners cannot be omitted because without them the panel will simply not lie flat.